Pull Classes

  •   FWD – Four Wheel Drive Trucks
  • SST (Diesel) – Super Stock Diesel Tractors 
  •    SST (Open) – Super Stock Tractors
  • LSS – Light Super Stock Tractors 
  •    MINI – Mini Modified Tractors
  • MOD – Modified Tractors  
  •    PS – Pro Stock Tractors
  • SEMI – Super Semis 
  • SF – Super Farm Tractors
  • TWD – Two Wheel Drive Trucks 
  •   UNL – Unlimited Modified Tractors
  • LT UNL – Light Unlimited Tractors 
  •    SSD 4×4 – Super Stock Diesel 4×4 Trucks
  • LIM PS – Limited Pro Stock
  •    LT PS – Light Pro Stock


FWD – Four Wheel Drive Trucks

Perhaps the closest in appearance to what the average pulling fan drives on the street, the Modified Four Wheel Drive trucks are also the only “naturally aspirated” division in NTPA competition and utilize both rear and front wheels to pull. With no turbo charger or super charger to force air into the engine, a competitor in this division must rely on the engine itself to pump as much air as possible and that means that engine settings like the proper air/fuel ratio are more important than ever. Chassis setup, gearing, tire pressure, and the driver all must be perfect to win in this division.

SSD – Super Stock Diesel Tractors
You might call the “Super Stock” an unlimited version of the “farm” appearing tractor classes. Although they may appear “stock” on the outside, they produce many times over their factory rated horsepower. As the name implies, diesel is the only fuel allowed in the Super Stock Diesel division. These International and John Deere machines produce around 2,500 to 3,000 horsepower with their “stock engine” having up to four turbo chargers flowing the air mixture.

SSO – Super Stock Open Tractors
The “Super Stock Open” class generates more power than any NTPA “stock” division. From their tube frame component chassis to their highly modified engine, these aren’t your granddad’s John Deere, Case IH, or various other brand models found in agriculture – hardly! These machine can create in excess of 5,000 horsepower weighing 8,000 lbs. In the “Open” division, most of the engines have been modified to run on methanol fuel, although rarely fans will see a diesel fueled Super Stock joining in the fray. Unlike all other forms of NTPA “Stock” classes, the alcohol tractors do not blow plumes of black smoke.

LSS – Light Super Stock
The Light Super Stock class is a very colorful division in that many manufacturers are represented, such as Case IH, John Deere, Agco Allis, Oliver, Massey Ferguson, Ford, and even Deutz. Unlike all the other NTPA Grand National divisions that are born and bred from the agricultural fields of America , the Light Super Stock division features machines that both utilize diesel and alcohol as fuel choices. Weighing in at 6,000 pounds, the wheel speeds and wild rides are sure to please the crowds !!!!

MINI – Mini Modified Tractors
The “Minis” are the undisputed kings in the motorsport world when it comes to “power to weight” ratio. An amazing one horsepower per pound combined with a wheelbase of less than 100″ also qualifies the “Minis” as the “wildest ride on four wheels”, although they aren’t using all four most of the time. At 2,050 lbs., the Minis are the lightest division in NTPA competition and are probably the toughest to drive. Keeping the tractor in a straight line heading down the track is the biggest challenge a driver in this division faces.

MOD – Modified Tractors
Whereas the “Unlimiteds” can use virtually any number and type of engines, the “Modifieds” are limited in type and number of engines depending on the combination. Competing at a maximum weight of 7,500 lbs., many times you will see competitors in this division add a motor or two and compete in the Unlimited division. Although the Unlimiteds only compete on the NTPA Grand National Circuit, the Modifieds can be seen at NTPA Regional and State level with further limitations on allowed engine number and combination for those levels of competition.

PS – Pro Stock Tractors
The “Pro Stock” division gets us a little closer to those tractors you see in the fields. This division by rule is restricted to only one turbocharger. But with a massive 6″ exhaust, that big whistle can blow a really low note. Between that and their 680 cubic inch displacement, the deep-growling Pros are know to the dedicated fan by sound as much as by sight. Pro Stocks compete on 24.5″ wide tires and at 10,000 lbs., they are the heaviest of the tractor classes.

SEMI – Super Semis
Tractor Pulling is called the “Heaviest Motorsport on Earth” and the Super Semis are the heavyweights of tractor pulling. Weighing in at 20,000 lbs., these behemoths overshadow everything else on the pulling track and for that matter, anything else in motorsports. When they come thundering down the track, the heavier the load gets, the harder they pull. Sometimes you wonder if they’ll ever stop. The Super Semis are one of the most popular divisions of NTPA pulling.

SF – Super Farm Tractors
Super Farm Tractors (SFT) are closest to “off the farm” workhorses as you will find in NTPA competition. Engine size is limited to 640 cubic inches, they must use the OEM manifold and heads for that brand engine and can only use one 3″ turbo. Diesel fuel is still the only permitted fuel and tire sizes are also the same as Pro Stock Tractors. The fuel pump is limited to a “P” type pump and competitors must use the stock intake and exhaust manifold for that brand engine. The Super Farm class is extremely competitive and any competitor has a shot at winning.

TWD – Two Wheel Drive Trucks
These are the “Funny Cars” of tractor pulling – the “wheel standers”. The sheet metal provides all the personality: From an old Luv to a new Colorado, an ancient Model T to a modern Ranger, and even the occasional Packard, Jeep, or Fiat.”. Regardless of the vehicle bodies, they will all be powered by a big block V-8 with a super charger in most cases, but with a sprinkling of turbo-chargers. This division competes at a weight of 6,200 lbs.

LT UNL – Light Unlimited Tractors

This division was bornin 2012 and was changed in 2014 to allow only two automotive engines. Since then, it has drawn competitors both brand new to pulling and from other divisions to answer the challenge of getting all that horsepower to fit in a 6,000-lb. package. Too light up front and you’ll go for a crazy ride; too heavy and you’ll blow the tires off at the line. Enjoy the Light Unlimiteds’ balancing act as they tiptoe that tightrope to a Tomah Trophy!

UNL – Unlimited Modified Tractors

Born in 1970 as one of the NTPA’s original divisions, the world’s most powerful competition vehicles utilize all sorts of engine combinations. Unlimiteds are bounded only by tire size (30.5), length (14″), weight (8,000 lbs.), and the imagination of the builders, who over the years have incorporated power plants from fighter planes, tanks, boats, and helicopters. These days, the most common configuration is four or five supercharged automotive engines, any one of which could power a top fuel dragster for a fast quarter mile. Working in unison, these units punish a dirt track and sling a weight transfer with well upwards of 10,000 horsepower, embodying the NTPA’s motto: “Hear the Power, Feel the Noise.”

Limited Pro Stock Tractors

Like their small-cube/big-turbo brethren, the Limited Pros (640 ci/4.1″ charger) are still up and comers on the Association’s national circuit. But their appeal is in both their farm tractor appearance and sled-dragging performance: The Limiteds don’t give up until the last piston stroke. Watch them run in Tomah for a shot at a Region III title.

Light Pro Stock Tractors

Light Pros are among the NTPA’s newest divisions. With engines at 540 cubic inches and turbos restricted on the exhaust side to 4.5″, their 8,500-lb. allowance must also incorporate an OEM chassis. That combination can make for an exciting ride down the Tomah twin tracks to compete for a Region III championship and big-stage bragging rights.